Processing apparatus for etching the edge of a silicon wafer

Abstract

The present invention provides a processing method of outermost periphery edge part of silicon wafer comprising, etching the outermost periphery edge of silicon wafer by activated species gas generated in plasma. The plasma activated species gas can be generated by dissociation of, for example, sulfur hexafluoride gas in a discharge tube 8 . Further, provides a processing apparatus for etching of outermost periphery edge of silicon wafer by means of plasma etching method comprising, a means to hold and rotate a silicon wafer 1 , a container 5 which covers all surface of silicon wafer except a part of outermost periphery edge, a vacuum chamber 10 which contain said container and a plasma generating means 11.

What is claimed is:  
     
       1. A processing apparatus for etching of outermost periphery edge part of silicon wafer by means of plasma etching method possessing a means to hold and rotate a silicon wafer, comprising a container which covers the surface of silicon wafer except a part of outermost periphery edge, a vacuum chamber which contains said container and a plasma generating means having a process gas composed of sulfur hexafluoride gas. 
     
     
       2. The processing apparatus for etching of outermost periphery edge of silicon wafer of  claim 1 , wherein inside of the container which covers all surface of silicon wafer except a part of outermost periphery edge is maintained at plus pressure relative to the inner pressure of the vacuum chamber which contains said container by nitrogen gas or other inert gas. 
     
     
       3. An apparatus for etching the outermost periphery edge of a silicon wafer by plasma etching which comprises, 
       a rotating shaft on which is provided a table that rotates with the shaft,  
       the table is adapted to receive and hold a circular silicon wafer which rotates with the shaft,  
       a dispersion preventing container is disposed around the silicon wafer table and shaft, except for a small slit opening at an end of the container through which an outer edge part of the silicon wafer is exposed, and an opening through which the rotating shaft passes,  
       an inert gas supply line is connected to the dispersion preventing container to supply an inert gas and maintain a positive gas pressure in the dispersion preventing container,  
       there is disposed near to and in operative relationship with the small slit opening and the exposed part of the outermost periphery edge of the silicon wafer, a nozzle which is directed at the periphery edge of the silicon wafer is disposed near to and in operative relationship with the small slit opening and the exposed part of the outermost periphery edge of the silicon wafer.  
     
     
       4. The apparatus of  claim 3  wherein the dispersion preventing container and the gas nozzle are contained within a vacuum chamber which is maintained at a negative pressure relative to the pressure in the dispersion preventing container.